# Service bulletin 36774.4.0

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 11037965
- Published by NHTSA: 2026\-10\-05
- Manufacturer's number: 36774.4.0
- Manufacturer's date: 2026\-09\-17
- NHTSA component: POWER TRAIN

## NHTSA's summary

This is a Technical Journal: Text plus 1 PDF \-\- DTC TCM P277C07 set. If the TCM DTC listed below is set, A new transmission hardware solution has been introduced starting from transmission serial number 25M8L30144, which serves as a defined break point for updated production. \*If the DTC is confirmed and the transmission serial number is after the break point: Do NOT replace the transmission follow the advise under "Service".

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2026/MC-11037965-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2026/MC-11037965-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Transmission and driveline

## Trouble codes named

P277C

## Vehicles listed

- 2024 VOLVO S60MHEV
- 2024 to 2026 VOLVO S90MHEV
- 2024 VOLVO V60CCMHEV
- 2026 VOLVO XC40MHEV
- 2025 to 2026 VOLVO XC60MHEV
- 2024 to 2027 VOLVO XC90MHEV

## Other bulletins for the same vehicles and component

- [37871.1.0](/bulletins/11036242.md), 2026-08-18, Service bulletin: POWER TRAIN. This is a TJ \- Text only no attachments \- During the first year in production of the new engines, with the updated transmission calibration, we need to follow up on transmission shift quality. For this reason, it is not allowed to perform any repairs on the transmission before RTS \(Volvo Cars Retailer Technical Support\) has been contacted. No transmissions should be repaired or replaced without approval or a request from RTS.
- [36774.3.0](/bulletins/11034990.md), 2026-07-14, Service bulletin: POWER TRAIN. This is a Technical Journal: DTC TCM P277C07 set. If the TCM DTC listed below is set, A new transmission hardware solution has been introduced starting from transmission serial number 25M8L30144, which serves as a defined break point for updated production. \*If the DTC is confirmed and the transmission serial number is after the break point: Do NOT replace the transmission follow the advise under "Service".
- [36496.10.0](/bulletins/11033734.md), 2026-06-08, Service bulletin: POWER TRAIN. This is a Technical Journal: Intermittent knocking noise during acceleration. If the sound corresponds to attached sound file, change front drive shafts to the below part numbers.
- [37299](/bulletins/11029172.md), 2026-03-02, Service bulletin: POWER TRAIN. This a Technical Journal plus 1 mp4 file If a customer experiences noise from the rear of the vehicle, often generated at low speeds and during cold climate conditions \(listen to the attached file TJ\_37299\_1.mp4 as a reference\), please follow the advice under "Service". Note\! Do not replace any parts, as this will not solve the issue.\&\#13; Analysis is ongoing, and this journal will be updated accordingly.\&\#13; \*The estimated timeline for the solution is during quarter 3 of 2026.
- [37228](/bulletins/11027191.md), 2026-01-07, Service bulletin: POWER TRAIN. This is a Technical Journal: Vehicle jerks in low speed when Start/Stop is active. Improved software is introduced from version 3.5.14.\&\#13;
- [36814](/bulletins/11020543.md), 2025-07-09, Service bulletin: POWER TRAIN. This is a Technical Journal: Transmission Shifts From D or R to P Immediately After Starting. This symptom can occur if the driver changes the position of the gear shifter from P to D or R very quickly after starting the engine and the starting process is not completed. Inform the driver to pause briefly after starting the vehicle before shifting into D or R.
- [37228](/bulletins/11020538.md), 2025-07-09, Service bulletin: POWER TRAIN. This is a Technical Journal: Vehicle jerks in low speed when Start/Stop is active. Improved software is introduced from version 3.5.14.\&\#13;
- [36814](/bulletins/11020524.md), 2025-07-09, Service bulletin: POWER TRAIN. This is a Technical Journal: Transmission Shifts From D or R to P Immediately After Starting. This symptom can occur if the driver changes the position of the gear shifter from P to D or R very quickly after starting the engine and the starting process is not completed. Inform the driver to pause briefly after starting the vehicle before shifting into D or R.
- [35732](/bulletins/11016899.md), 2025-04-09, Service bulletin: POWER TRAIN. This is a Technical Journal: Clicking sound from transmission area.\&\#13; This is considered a normal operating characteristic/function of the vehicle.\&\#13;
- [36989](/bulletins/11016890.md), 2025-04-09, Service bulletin: POWER TRAIN. This is a Technical Journal: Vehicle jerks and TCM DTC P071164 set. A software solution is introduced from version 3.4.4.

JSON: [/v1/bulletins/11037965](/v1/bulletins/11037965)

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